HDMI Sound Bumblebee

Hello All

I'm trying to get hdmi sound output with bumblebee, aplay -l only detects my internal speakers when i have my "hybrid graphics" enabled, but it's detected if i switch to "discrete only" i've tried using "optirun" which is the terminal command to activate nvidia etc "optirun aplay -l" still not detected, I've tried following the wiki but all the fixes seem to depend on the info gathered from aplay -l output, I've installed all the recommended pulse audio and alsamixer packages.

Any advice please ?